Developmental processes contributing to the emergence of self- regulatory (Sly skills in children with mental retardation (MR) are not well known, but likely involve differential family processes. SR contributes directly to successful behavioral, emotional, and social development, and later mental health. Therefore, studying the developmental processes contributing to SR is crucial for children with MR, as they are at greater risk for psychopathology than are typically developing (TD) children. General cognitive and socialization factors influence the development of self-regulatory processes for young children, however ways in which specific child characteristics and the quality of parent-child interactions differentially contribute to the emergence of SR skills for children with and without developmental delays (DD) is less clearly delineated. This proposal contrasts two models of the emergence of SR Both address processes by which temperament and cognition differentially influence parent-child interactions and the emergence of SR skills. Relation of temperament and cognition to SR are proposed to vary as a function of developmental status. Further, specific parenting behaviors during parent-child interactions are proposed to differentially mediate the relationship of cognition, temperament and SR competency. A total of 246 children with (N=109) and without (N=13'n DD participated in lab- based parent-child interactions. Parents completed self-report surveys. The sample is 58% male and 40% non-White. The research design is descriptive and correlational in nature.